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Aerosol concentrations over the surf were measured during the EOPACE (Electro-Optical Propagation Assessment in Coastal Environment) Surf-i experiment in La Jolla, California. Particle size distributions were measured on the beach (at three levels) and across the surf (one level). Concentrations of droplets smaller than i im in diameter are little affected by the surf, while those with diameters in the 1-10 im range increase by up to two orders of magnitude. Clear vertical gradients were observed, which vary with particle size. No relation could be established between the surf production and wind speed or wave properties. Extinction coefficients at visible and infrared wavelengths calculated from the particle size distributions show that these are enhanced by a factor of 30 to 100, depending on the wavelength. Using the measured concentrations as boundary condition, calculations with a simple dispersion model show the gradual decrease in the concentration with fetch in off-shore winds. In on-shore winds the surf-enhanced aerosol concentration is effective over only a short range, but nevertheless significant transmission losses may occur. Obviously, these conclusions apply only to the surf encountered during this specific experiment. The effects of the surf in other areas and other ambient conditions will be assessed from the analysis of data collected at a different location and in different conditions.

By screening databases of human expressed sequence tags, we have identified three new homologues of MRP1, the gene encoding the multidrug resistance-associated protein, and cMOAT (or MRP2), the canalicular multispecific organic anion transporter gene. We call these new genes MRP3, MRP4, and MRP5. MRP3, like cMOAT, is mainly expressed in the liver. MRP4 is expressed only at very low levels in a few tissues, and MRP5, like MRP1, is expressed in almost every tissue tested. To assess a possible role of these new MRP homologues in multidrug or cisplatin resistance, a large set of resistant cell lines was examined for the (over)expression of MRP1, cMOAT, MRP3, MRP4, and MRP5. We find that even in cells selected for a low level of resistance, several MRP-related genes can be up-regulated simultaneously. However, MRP4 is not overexpressed in any of the cell lines we analyzed; MRP3 and MRP5 are only overexpressed in a few cell lines, and the RNA levels do not seem to correlate with resistance to either doxorubicin or cisplatin. cMOAT is substantially overexpressed in several cell lines, and cMOAT RNA levels correlate with cisplatin but not doxorubicin resistance in a subset of resistant cell lines. Our results emphasize the need for gene-specific blocks in gene expression to define which transporter contributes to resistance in each resistant cell line.

Background—Little is known about the comparability of outpatients with irritable bowel syndrome (IBS) and patients with IBS in primary care with regard to severity of complaints, perceived limitations, other aspects of the complaints, and sex differences.Aims—To compare outpatients with IBS with primary care patients with IBS.Patients—One hundred and nine patients with IBS were recruited from general practices in Amsterdam and 86 patients with IBS were recruited from the outpatient clinic of the Department of Internal Medicine of the University Hospital in Nijmegen.Methods—Each patient completed a questionnaire on demographic variables, abdominal complaints, related complaints, and attributed causes of their abdominal complaints. The scores of the two groups were compared by univariate and multivariate analysis.Results—The outpatient group contained significantly more men, reported more severe abdominal pain, more frequent complaints, more interference with daily activities, and a higher degree of avoidance of activities (pConclusions—Female outpatients consider their complaints to be more serious and interfering than do patients with IBS in primary care. Male outpatients were comparable to primary care patients with IBS. More research needs to be done into sex specific differences in IBS and into the factors that influence the decision to refer a patient with IBS.

Background Although participation in paid work is an important life area for patients and loss of work might have severe consequences for the physical, emotional and financial situation of patients, no recommendations for the assessment of work ability exist in rheumatology practice. Objectives To explore whether rheumatologists and rheumatology nurses a) consider worker participation as a treatment target and b) need tools to improve attention and care for participation in paid work. Methods Two comparable web-based surveys were developed and disseminated among rheumatologists and rheumatology nurses in the Netherlands. The questionnaires focussed on (a) existing practice in assessment of work ability of the patients, (b) priorities for different treatment targets (including work) and confidence with treatment plans, to be scored on a 0/no priority-10/highest priority scale, (c) need to have a standardized tool to address problems at work and (d) possible barriers to apply such tool. Results From the health care providers, 104 rheumatologists (40%) and 103 nurses (50%) in the Netherlands filled in the survey. 97% of the rheumatologists and 99% of the nurses considered optimal worker participation a treatment target. Rheumatologists prioritised the topic, mean (SD) 7.6 (1.3) after reducing disease activity 9.4 (0.9), pain 8.9 (1.2), and improving self-management 8.3 (1.2). Nurses also prioritised the topic 7.8 (1.2) after reducing disease activity 9.3 (0.9), pain 9.2 (1.0) and improving self-management 8.4 (1.2) but in addition considered reducing fatigue (8.4 (1.3) more important. Both groups acknowledge the importance of work participation but the gap between priority and confidence with treatment plans, 1.5 (1.4) and 2.2 (2.4) for rheumatologists and nurses respectively, shows that support may be necessary. Both rheumatologists and nurses considered a tool to assess problems at work and effective interventions important and necessary but effects should be examined. Of the rheumatologists, 52 % limitations in time a barrier for an active approach in daily practice and 28% referred their patients with problems regarding work participation to the rheumatology nurse. Conclusions The study showed that rheumatologists and nurses consider worker participation as an important treatment target. However, they express a need for (evidence based) tools to identify patients that are at risk for adverse work outcome and for better insight into effective interventions to improve the quality of care regarding work. Acknowledgements We thank Mr. R Buijs for the data analysis Disclosure of Interest C. W. J. Logtenberg- Rutten Grant/research support from: Abbvie, Y. J. van Eijk- Hustings Grant/research support from: Abbvie, E. Stadermann Employee of: Abbvie, M. J. Scholte- Voshaar Grant/research support from: Abbvie, M. M. Hazes Grant/research support from: Abbvie, A. E. Boonen Grant/research support from: Abbvie

Various atmospheric propagation effects are limiting the long range performance of electro-optical imaging systems. These effects include absorption and scattering by molecules and aerosols, refraction due to vertical temperature gradients and scintillation and blurring due to turbulence. In maritime and coastal areas, ranges up to 25 km are relevant for detection and classification tasks on small targets (missiles, pirates). From November 2009 to October 2010 a measurement campaign was set-up over a range of more than 15 km in the False Bay in South Africa, where all of the propagation effects could be investigated quantitatively. The results have been used to provide statistical information on basic parameters as visibility, air-sea temperature difference, absolute humidity and wind speed. In addition various propagation models on aerosol particle size distribution, temperature profile, blur and scintillation under strong turbulence conditions could be validated. Examples of collected data and associated results are presented in this paper.©2013 Society of Photo-Optical Instrumentation Engineers (SPIE)

The MAPTIP (marine aerosol properties and thermal imager performance) experiment was organized as part of a project to assess atmospheric effects on the detection and identification of targets using thermal imagers in coastal areas. The experiment took place at the North Sea from 11 October - 5 November 1993 and was centered around Meetpost Noordwijk, a research tower at 9 km from the Dutch coast. Platforms included a beach station, ship, research airplane, P3 Orion, helicopter and three buoys. The objectives were centered around the characterization of the atmosphere (aerosols, extinction, turbulence, refractivity, and the vertical and horizontal variations of the relevant meteorological parameters), in combination with detailed measurements of optical and IR effects using thermal imagers, visual cameras, transmissiometers and visibility meters. Detection ranges of various targets were determined and IR properties of extended targets were continuously monitored using radiometers. Extensive studies were made on polarization effects, backgrounds and effects of sun glint. An overview of the experimental efforts and the ensuing analysis and modeling studies are presented. MAPTIP was the first validation of some recently developed atmospheric propagation models, including aerosol models, in a coastal environment. MAPTIP has yielded a wealth of data for the development of advanced aerosol models, description of horizontal variability, improvement of point target detection algorithms, validation of detection range models, and EOTDA validation.

During the MAPTIP experiments in the Dutch coastal waters, 11 October - 5 November 1993, transmission curves were determined from the intensities of the image of a point source suspended from a helicopter at ranges between 0.5 and 6 NMi. The images were recorded with a 10 micrometer USFA 9092 camera from the MeetPost Noordwijk, a research tower in the North Sea at 9 km from the Dutch coast. The transmission determined from the point source intensities at several ranges is compared with calculated values. The transmission is determined by extinction due to aerosols and molecular species in the propagation path. Both contributions can be determined using code using measured size distributions. Also effects of path radiance and background on the image intensity are considered. In this coastal area, and the off- shore winds that were usually encountered during MAPTIP, the aerosol size distributions are known to be a complicated mixture of continental and marine aerosols. Hence the common aerosol models, that usually work well over the open ocean, are often not so reliable in a coastal environment. An attempt is made to assess the influence of marine and anthropogenic contributions to the aerosol on the detection range of point targets in a coastal atmosphere.

Aerosol particle size distributions and meteorological parameters were measured during the MAPTIP experiment in the fall of 1993 in the vicinity of MeetPost Noordwijk (MPN), a platform at 9 km from the Dutch coast. One data set was collected at MPN, the other on board of a ship that sailed down and cross wind trajectories. from MPN to a distance of 200 km. Both the aerosol concentration and extinction respond to variations in the meteorological conditions. For down wind trajectories, the responses at ship and platform are observed with a delay in accordance with the time it takes for an air mass to travel from one to the other. For cross wind trajectories, the responses are observed simultaneously at ship and platform. The comparison of ship and platform also shows that the meteorological conditions change as a function of fetch in off-shore winds. This fetch effect does not show up clearly in the aerosol concentrations, which suggests that in off-shore winds the influence of the land (natural, industrial and urban aerosol) extends up to more than 200 km from the coast.

Cumulus oocyte complexes (COCs) and cumulus oocyte complexes connected to a piece of the membrane granulosa (COCGs) were isolated from bovine antral follicles with a diameter of 2 to 8 mm. After culture of COCGs without gonadotrophic hormones for 22 hr approximately 50% of the oocytes were still in the germinal vesicle (GV) stage. Histology of the COCGs showed that the pieces of the membrana granulosa were free of thecal cells and parts of the basal membrane. This indicates that the membrana granulosa solely inhibits the progression of meiosis. To investigate the effect of gonadotropins on the resumption of meiosis of oocytes from small and medium sized antral follicles, COCs and COCGs were cultured with or without rec-hFSH or hCG. Addition of 0.05 IU rec-hFSH to the culture medium of COCGs resulted in germinal vesicle breakdown in 97.8% of the oocytes compared to 46% in the control group, and an increase of the diameter of the COCs (479 microns vs. 240 microns in the control group). Addition of 0.05 IU hCG to the culture medium had no effect on nuclear maturation (47.2% GV vs. 48.5% GV in the control group) nor on cumulus expansion (246 microns vs. 240 microns in the control group). RT-PCR on cDNA of the follicular wall, cumulus cells, granulosa cells, COCs, and oocytes revealed that mRNA for FSH receptor was present in all cell types except oocytes. mRNA of the LH receptor was detected exclusively in thecal cells. Nucleotide sequence analysis and alignment of the cloned PCR products showed the presence of two isoforms of the FSH receptor mRNA and two isoforms of the LH receptor mRNA. It is concluded that, in vitro, resumption of meiosis of oocytes, originating from small and medium sized antral follicles and meiotically arrested by the membrana granulosa, is triggered by FSH and not by LH. This is supported by the fact that receptors for FSH, but not for LH, are transcribed in the cumulus and granulosa cells of these follicles.

The influence of bovine lymphocyte antigen (BoLA) complex polymorphism on subclinical progression of bovine leukaemia virus (BLV) infection was investigated in 41 Holstein-Friesian cows from two herds in Italy. All cows were seropositive for BLV and 22 had persistent lymphocytosis (PL). BoLA-A specificities were defined by serology, and class II haplotypes were defined based on restriction fragment length polymorphism (RFLP) and polymerase chain reaction (PCR)-RFLP analysis of DQ and DR genes. Chi-square analysis revealed a significant and absolute association of haplotype DQA*3A-DQB*3A-DRB2*2A-DRB3.2*11 with resistance to PL (P chi 2 = 0.028, relative risk (RR) = 0.061). Consistent with this observation, multiple regression analysis revealed that animals carrying this haplotype had lower lymphocyte counts (P = 0.0057). By contrast, haplotype DQA*12-DQB*12-DRB2*3A-DRB3.2*8 was associated with susceptibility to PL (P chi 2 = 0.043, RR = 9.625) and increased lymphocyte counts (P = 0.0537). These results confirm the association of haplotype DQA*3A-DQB*3A-DRB2*2A-DRB3.2*11 with resistance to PL, and substantiate earlier findings of haplotype DQA*12-DQB*12-DRB2*3A-DRB3.2*8 as a risk factor for subclinical progression to PL in BLV-infected Holstein-Friesian cattle.

The expression of both components of the high-affinity leukaemia inhibitory factor receptor, LIFR beta and glycoprotein 130 (gp130), was investigated in human oocytes and individual in-vitro cultured preimplantation embryos by reverse transcription-polymerase chain reaction (RT-PCR). Messenger RNA of both LIFR beta and gp130 was detected in as little as 1/30 and 1/12 sample equivalents of cDNA respectively, in oocytes (n = 4), 4-cell and expanded, blastacyst stage embryos. LIFR beta but not gp130 transcripts were detected at the 2-, 8- and 10-cell stages, and in cavitating and hatched blastocysts. In order to exclude a simian origin of these PCR products resulting from the Vero cell line that was used as a feeder during culture to the blastocyst stage, they were digested with restriction endonucleases Taql (LIFR beta) or Kpnl (gp130). Their human origin was confirmed. The results support an earlier finding of LIFR beta mRNA expression in human blastocysts, and extend these results to earlier stages and oocytes. This is the first report of LIFR beta and gp130 transcription in human oocytes. Taken together these results demonstrate that transcription of LIFR beta and gp130 takes place throughout human preimplantation development, and suggest that functional LIF receptors might be present at these stages. These results further confirm the feasibility of performing mRNA phenotyping of multiple genes with RNA derived from a single preimplantation stage embryo.

The marine aerosol properties and thermal imager performance trial (MAPTIP) was conducted by NATO AC/243 Panel 04/RSG.8 and 04/RSG.5 in the Dutch coastal waters during the fall of 1993. The main objectives of the trial were (1) to assess marine boundary layer effects on thermal imaging systems and (2) to improve and validate vertical marine aerosol models with emphasis on coastal and near-surface effects. Aerosol and meteorological instruments, as well as thermal imagers and calibrated targets, were utilized on two off-shore platforms, a beach station, three airborne platforms, and buoy systems. This network of instrumentation has provided a comprehensive data base of aerosol size distribution profiles and relevant meteorological variables throughout the marine atmospheric boundary layer. Atmospheric turbulence and refractivity effects in the IR and rf bands were measured to assess the marine boundary layer effects on the degradation of thermal images. Thermal imagery in both the 3 - 5 and 8 - 12 μm bands was included to provide ground truth for assessing the low-level propagation effects near the ocean surface. Calibrated targets at different altitudes were observed to the maximum observable range under a wide variety of conditions. These data are to be used for the development and validation of IRST models and IR ship signature models, and for determining the effects of marine-generated aerosols, turbulence, and meteorological profiles on their performance.

During the fall of 1993, a field experimental study on marine aerosol properties and thermal imager performance was conducted in the Dutch coastal waters. Aerosol and meteorological instruments, as well as thermal imagers and calibrated targets, were used at several platforms and locations: the Dutch Meetpost Noordwijk (a tower 9 km from the Dutch coast), a beach station in Katwijk, the oceanographic research vessel Hr. Ms. Tydeman, a Lynx helicopter, a P3 Orion, the NCCOSC RDT&E Div airborne platform, and buoy systems. This network of instrumentation was used for obtaining a comprehensive data base of aerosol size distribution profiles and relevant meteorological variables throughout the marine atmospheric boundary layer. Thermal imagery has been included to provide ground truth for assessing the low- level propagation effects near the ocean surface. Measurements have been made of atmospheric turbulence and refractivity effects at wavelengths in the IR and visible, to assess the marine boundary layer effects on the degradation of thermal images. Calibrated targets at different altitudes were observed to the maximum observable range under a wide variety of conditions in both the 3 to 5 and 8 to 12 micrometers bands. These data will be used for the development and validation of IRST models and IR ship signature models with the view of determining the effects of marine-generated aerosols, turbulence and meteorological profiles on their performance.

Propagation of electro-magnetic radiation in the marine atmospheric boundary layer is discussed, with emphasis on aerosol effects on extinction. An outline of the atmospheric module of the FEL-TNO range predictor is presented. This model is developed to predict the maximum detectable range of a sensor-target combination both for open ocean and coastal marine environments. The effect of meteorological parameters (wind speed, wind direction, relative humidity and air-sea temperature difference) on the maximum detectable range is discussed.

An analysis is presented of aerosol particle size distributions measured over the North Atlantic and extinction coefficients derived from these data. Two empirical models, an aerosol model and an extinction model, are formulated in terms of simple meteorological parameters (wind speed, relative humidity, air temperature and sea temperature). The choice of these parameters is based on considerations of their effects on the aerosol physics in the marine atmosphere. The performance of the models for predictions of the extinction coefficients at (laser) wavelengths in the visible and IR atmospheric windows is assessed. The results are compared with predictions of the Navy Aerosol Model (NAM).

Aerosol particle size distributions were measured during the HEXMAX experiment in the fall of 1986 from Meetpost Noordwijk (MPN), a tower in the North Sea at 9 km from the Dutch coast. Extinction coefficients for wavelengths from 0.55 to 10.6 micrometers were calculated using a Mie routine. The initial analysis showed that straightforward empirical modeling in terms of meteorological parameters did not yield meaningful results. Therefore, the aerosol particle size distributions were modeled in terms of parameters that determine the production, dispersal, and deposition of the aerosol in the coastal marine boundary layer. For an adequate description, the database had to be partitioned into wind-direction sectors based on industrial, rural continental, and predominant marine influences. Based on this empirical aerosol model, the extinction coefficients can be predicted with an accuracy of better than a factor of 1.8. The reliability of the model decreases during frontal passages and periods of rain. The model is validated versus the experimental data and by comparison with the Navy Aerosol Model.© (1992) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Photolithography on high topography substrates, such as the sidewalls or the bottom of cavities and trenches created by bulk micromachining, enables the design of complex three-dimensional structures. When a contact lithography system is used to pattern such substrates, local gaps exist between the mask and the substrate. In this paper we investigate the deformation of patterns as a result of these local gaps. We determine the position accuracy and the minimum size of features that can be patterned as a function of the gap distance. Deformations introduced by the optical system are quantified for a common exposure tool, and compared to pattern deformation due to variations in photoresist layer thickness. Finally, methods to improve the quality of patterns transferred through gaps up to 350 ?m are discussed

In the lowest excited triplet state, benzil (1) adds highly regio- and stereoselectively to the olefin 2-morpholinoacrylonitrile (2) to form solely the oxetane 5.

The performance assessment of electro-optical (EO) systems with propagation prediction codes requires accurate atmospheric models. The model that is most frequently used for the prediction of aerosols and their effect on extinction in the marine atmosphere is the U.S. Navy aerosol model (NAM) (Gathman, 1983). The NAM was developed for open ocean applications, where it works well. In coastal areas, however, the performance of the NAM may be reduced (Tanguy et al., 1991; De Leeuw, 1993). Based on an extensive series of measurements on the Irish Atlantic coast, an extension of the NAM for the coastal zone is proposed. As in the NAM, the dependence of the aerosol concentration on meteorological parameters is parameterized using empirical coefficients. The effect of the coastal zone is modeled as a function of fetch. A reasonable agreement is found between the model and the aerosol size distributions as measured on the island Inisheer, west of Galway Bay, Ireland.

A strain of the methylotrophic yeast Hansenula polymorpha, A16, has been developed that expresses the guar alpha-galactosidase gene to 22.4 mg/g dry cell weight in chemostat cultures at a dilution rate of 0.1 h(-1). This corresponds to more than 13.1% of soluble cell protein, of which 56-62% is secreted into the medium. The alpha-galactosidase gene was flanked by the promoter and terminator sequences of the H.polymorpha mox gene, which can direct expression of the mox gene itself more than 30% of total cell protein under methanol growth. The expression cassette (pUR3510) based on the Saccharomyces cerevisiae plasmid, YEp13, was integrated into the genome. Such transformants were stable in chemostat cultures and exhibited 100% stability for both alpha-galactosidase+ and leu+ phenotypes. Chemostat cultures produced higher levels of alpha-galactosidase with higher specific productivities expressed as mg alpha-galactosidase g(-1) h(-1) compared to batch cultures.

An empirical model has been developed to predict aerosol particle size distributions from a set of relatively simple meteorological parameters. The model is based on measurements taken at Meetpost Noordwijk (MPN) (North Sea) during the Humidity Exchange Over the Sea Main Experiment in 1986. The air masses at MPN contain a mixture of continental and marine aerosol. The relative contribution of each type of air mass strongly depends on the wind direction. Partitioning the aerosol data set into eight wind sectors based on geographical considerations of the sources of natural, anthropogenic, and industrial aerosols is supported by analysis based on the wind speed dependence of the particle concentrations. For each wind sector the aerosol concentrations in the 0.2–15-μm diameter range were analyzed in terms of relative humidity, wind speed, air-sea temperature difference, and water temperature, that is, those parameters that determine the production, dispersal, and deposition of the aerosol. The model predicts the aerosol concentrations to within a factor of 1.7 (68% confidence limit). Model performance is reduced during frontal passages and in periods of rain and high relative humidity. This is illustrated with two case studies.

Optical excitation of solutions of 2-naphthaldehyde (NA) or 2-acetonaphthone in cyclohexane at 300 K leads in both cases to the formation of two triplet states. Time-resolved optical absorption spectroscopy reveals that these states decay relatively slowly with a decay rate amounting either to 3 × 106 or to 20 × 103 s–1(respectively in non-deoxygenated and deoxygenated solutions in cyclohexane), while they are interconverted at a higher rate. One of these two triplet states exhibits resonance Raman scattering and is characterized as a non-planar ππ* triplet state. The other triplet state may be characterized as an nπ* triplet state on the basis of the photochemical behaviour of 2-naphthaldehyde towards cycloheptatriene. A non-planar ππ* triplet state is also formed upon optical excitation of 9-anthraldehyde or 9-acetylanthracene, but in these cases no evidence for the existence of a dynamic equilibrium between two triplet states could be found. The measurement of transient dielectric losses at microwave frequencies indicates that the non-planar ππ* triplet states do not have the character of a twisted intramolecular charge-transfer state.

Experiments were carried out to characterize FEP (fluorinated ethylene-propylene copolymers) Teflon®bags as reactors for studies of photochemical reactions in sunlight of pollutants at low concentrations. Measurements of toluene loss, carbon monoxide oxidation and ozone formation in zero air in sun irradiated bags demonstrated a significant reactivity caused by the Teflon®film. The results indicate that such bags can be unsuitable for photochemical experiments at low (ppb) concentration levels.

In methanol-utilizing yeasts, catalase is an essential enzyme for the destruction of hydrogen peroxide generated by methanol oxidase (E.C. 1.1.3.13). It was found however that a catalase-negative mutant of Hansenula polymorpha is able to consume methanol in the presence of glucose in continuous cultures. At a dilution rate of 0.1 h-1, stable continuous cultures could be obtained during growth on methanol/glucose mixtures with a molar ratio of methanol/glucose between 0 to 2.4. In these cultures methanol oxidase was induced up to a level of 40% of that obtained in the wild-type strain. The hydrogen peroxide-decomposition activity of the mutant was studied in more detail by pulsing methanol to samples of steady-state cultures. Only after the addition of excess methanol the hydrogen peroxide-decomposing system became saturated, and the cells excreted hydrogen peroxide. This was accompanied by excretion of formaldehyde and a rapid loss of viability. The presence of extracellular catalase during a methanol pulse prevented the loss of viability. The nature of the alternative hydrogen peroxide-decomposing enzyme system remains to be elucidated. Its capacity strongly depended on the cultivation conditions and pretreatment of the cells. Cells grown on formaldehyde/glucose mixtures showed a lower methanol tolerance than those grown on the methanol/glucose mixtures. Freeze-drying of cells drastically enhanced the excretion of hydrogen peroxide, probably as a result of an inactivation of the decomposing system.

For mechanisms to guide small rotations and translations in instruments the use of elastic elements, such as torsion wires, membranes and plate springs, is widely accepted. In general the loads, necessary to move the body guided by an elastic element to a desired position, contain components which cause undesired motions. To minimize motions in directions, other than the desired rotation or translation, large values of the stiffnesses in these directions are required. These stiffnesses involve a certain stiffness in the direction of the desired motion. If this stiffness is too large it is possible to decrease this stiffness to an acceptable value by fitting a mechanism with negative stiffness parallel to the elastic element. In this paper a mechanism with negative spring stiffness will be discussed of which the action is based on the instability of the second order buckling state of a flat plate spring clamped at both ends. The action of the negative “spring” is independent of gravity. Moreover, a special advantage is that the mechanism contains no sliding parts.

The changes in cell wall strength of Hansenula polymorpha have been investigated in continuous cultures with respect to the recovery of methanol oxidase (MOX). Cultures grown on several substrate mixtures that enable induction of MOX have been compared with cultures grown on methanol as the sole inducer. The effects of dilution rate (D) on lysis properties have been studied. The cell wall strength was consistently influenced by growth media and D. Media containing glycerol/methanol showed the slowest lysis kinetics, with a large fraction of non-degradable cell wall material. In continuous cultures grown on a mixture of glucose and methanol both the resistance to zymolyase and the mean cell wall thickness increased at D 0.2 h−1, both protein and MOX release rates increase, reflecting a change in lysis mechanism due to the increased fraction of thin daughter cells. Kinetic analysis of zymolyase lysis using both physical and enzymatic methods provides information for achieving optimal recovery of MOX.

Many analyses of the depressed economy leave out of consideration the fact that many consumers and producers and probably also the government are now paralysed by fixation on the rationing they feel in their sales markets. Policies should be directed towards the destruction of the restrictions by which consumers', producers' and government behaviour is bounded. The increased attention since 1981 to an aggressive industry policy, specificly directed towards rein du strialization, and for the institutions required for designing and implementing such a policy, fit into the conviction that the current difficulties are due to market failures which prevent markets from generating and seminating the sufficiently accurate information required for efficiently allocating production factors.

The regulation of methanol oxidase (MOX) in Hansenula polymorpha has been studied in continuous cultures using a mixture of glucose and methanol (4:1 w/w) as carbon source. The study focused on the identification of stages in the biosynthesis affecting the formation of active MOX in glucose-methanol-grown cells. The levels of MOX mRNA, MOX protein in monomeric and octameric from, the ratio FAD/MOX, and the actual MOX activity have been quantified as functions of the dilution rate D. Hybridization studies with MOX mRNA probes showed an induction of MOX mRNA formation up to D = 0.29 h(-1). The induction of MOX protein synthesis (up to 37% of the cellular protein) is determined at low D values on the transcriptional level. The MOX activity at high D values is tuned by FAD incorporation and (post-) translation. Despite the high levels of MOX mRNA, decreasing levels of MOX activity and MOX protein were found at D values ranging from 0.14 t 0.29 h(-1). The maximal ratio FAD/MOX(6) was determined at D = 0.1 h(-1), which correlated with the maximal specific activity of MOX. In glucose-methanol media both protein level and MOX activity are repressed by increasing levels of residual glucose at high D values.

At ambient temperatures, hydrogen chloride is a strong bactericide. At a partial hydrogen chloride pressure of 30 mm Hg, the number of spore-bearing colony forming units present in straw dust particles of 0–32 μm was reduced by a factor-of more than 50 000 within 60 s. Naked spores of Bacillus subtilis were reduced in viability by a factor of 100 000 within only 10 s. Viability of vegetative cells of various kinds of bacteria was reduced by a factor of more than 107 within 10 s. The method of administration of the gas influenced the sterilization and had to be adapted to the geometry of the surfaces to be sterilized. The smaller the dust particles, the better the sterilization, seemingly due to the lower degree of inhibition of diffusion of gas to the microorganisms enclosed in the particles. Increases in treatment time and concentration of hydrogen chloride enhanced the sterilizing effect to a lesser extent when large dust particles were involved. The partial water vapour pressure did not influence the sterilization between 0.3 and 6 mm Hg. An increase in temperature decreased the sterilizing effect.

Many of the potential technical applications of alcohol oxidase (MOX; EC 1.1.3.13) are limited by the presence of high activities of catalase in the enzyme preparations. In order to circumvent laborious and costly purification or inactivation procedures, the induction of MOX in a catalase-negative mutant of Hansenula polymorpha has been studied. Emphasis was laid on the induction of activities of MOX and the dissimilatory enzymes in continuous cultures grown on various mixtures of formate/glucose and formaldehyde/glucose. In continuous cultures of the catalase-negative mutant grown on these mixtures, MOX can be induced efficiently. To obtain a stable and productive process, the ratio of the substrates is of critical importance. The optimal ratios of the mixtures for the catalase-negative strain for formate/glucose and formaldehyde/glucose were 3:1 and 1–2:1, respectively. Under identical cultivation conditions the wild-type strain showed similar induction patterns for MOX and the dissimilatory enzymes formaldehyde dehydrogenase (FaDH) and formate dehydrogenase (FoDH). The MOX levels in the catalase-negative strain were approx. 50% of those in the wild-type strain.

The CO stretching vibration dominates the ground-state Raman spectrum of 2-naphthaldehyde. The present study of the resonance Raman spectra of 2-naphthaldehyde and of various isotopically labelled 2-naphthaldehydes in the lowest ππ* triplet state, reveals the absence of lines due to vibrational modes involving displacements of atoms in the aldehyde group. All the lines in the triplet-state Raman spectra may be assigned satisfactorily to modes involving only displacements of atoms in the naphthyl group of the triplet-state molecule. This result supports the view that there is no conjugation between the naphthyl and the aldehyde group in the triplet state concerned. The synthesis of the isotopically labelled compounds is described.

A new arrangement for five-pass interferometry is presented together with a holder for wavelength scanning and mirror alignment. The parallelism of the mirror surfaces can be controlled precisely through independent rotations around two mutually perpendicular axes and the distance between the mirrors can be varied by 860 nm independently of the angular controls. Necessary modifications in the design for scanning in other wavelength ranges are outlined.

P. J. Verdoorn, born on 21 March 1911 in Amsterdam, studied economics at the Municipal University of Amsterdam. He received a Ph. D. degree from the Netherlands School of Economics at Rotterdam in 1943, and his doctoral thesis was written under supervision of Professor J. Tinbergen.1 After his doctoral examination (which is approximately the equivalent of a M.A. degree), he worked with the Dutch railways. In 1939 he joined the economics department of the Posts, Telegraphs and Telephones, the Dutch national communications organization. In these functions he was occupied with market research, which led him to apply econometric methods to market analytical problems. In 1939 he wrote, in co-operation with J. Tinbergen, an article on the demand for passenger-traffic by rail.2 During this time he probably also collected part of the material for an important book on market analysis which was published in 1949.3

This chapter is devoted to the development of wages and prices in the Netherlands since 1945. Equally, attention will be paid to policies to control and mitigate price and wage rises. During the whole period they have risen; in the beginning moderately, later on — particularly during the first half of the nineteen seventies — much faster. The whole period has been qualified as inflationary. In this chapter the word inflation will be used to indicate a persistent positive rate of change in prices. Consistently, policymakers have tried to moderate inflation. A stable price level has been one of the declared targets of economic policy1. For an assessment of counter-inflation policy, insight is required into the determinants of wage and price movements, into the interdependences between these variables and the other targets of economic policy and into the availability of policy instruments to attain these targets.